A great variety of devices have been developed to dispense air-treating vapors. A number of the recent inventions in this field include a liquid air-treating composition in an enclosure all or part of which is formed of a polymeric material (such as film) through which the air-treating composition can migrate to be released as a vapor at an outer surface. Use of such a permeable polymeric material controls the dispensing of air-treating vapors and tends to eliminate great variations in the rate of dispensing over the life of the product. Such products are considered advantageous in this regard when compared with the many air-treating products for which the rate of vapor release drops dramatically over the life of the product.
Products of the type having a sheet of permeable polymeric material to control the emission of air-treating vapors may be in a variety of forms. In some, the polymeric sheet covers a cylindrical container, while in others the liquid air-treating material is trapped between the permeable sheet and an impermeable plastic sheet. In still others, the permeable polymeric material forms a flexible pouch containing the air-treating liquid, which, prior to activation, is contained within an air-impermeable breakable container such as a glass vial, an impermeable plastic inner pouch, or the like. This invention is related primarily to products using a permeable pouch or bag to control the emission of air-treating vapors. An example of this type of pouch is disclosed in PCT Publication No. WO 82/02700.
For products having such pouches, it is often desirable for a number of reasons to contain and support the permeable pouch in some manner. For example, the user may wish to avoid contact with the air-treating material which occurs when the pouch is touched. Also, contact of the pouch with such finished surfaces, such as furniture, can harm the finish in some cases. Another important reason to contain and support such pouches is related to the rate of vapor dispensing, as will be discussed further in the following paragraphs.
When flexible permeable plastic bags containing liquid or other flowable material are used for vapor dispensing, the rate of dispensing will vary as the area of contact between the contained liquid and the inner surface of its enclosure varies. Pooling of the liquid at the enclosure bottom, as can often occur depending on the orientation of the enclosure, can substantially reduce the dispensing rate. The rate of vapor-dispensing is significantly increased and will remain very steady over the life of the product when the liquid is in contact with all or nearly all of the inner surface of the enclosure.
This problem is specifically pointed out in U.S. Pat. No. 4,130,245 (Bryson), entitled "Liquid Dispensing Package." See, for example, column 1, lines 23-40. The Bryson patent attempts to solve this problem by dividing the flexible plastic bag into a plurality of small chambers such that the liquid will not pool primarily in one location. While this approach may have some advantages for certain types of packages, it cannot readily be used when the flexible dispensing bag is of the type having a single chamber which encloses a smaller burstable inner storage container filled with an air-treating liquid composition to be released into the flexible dispensing bag upon bursting, as is shown in FIG. 1 of PCT Publication No. WO 82/02700.
The Bryson invention is not applicable to the problem of uneven dispensing for flexible dispensing bags of the type shown herein. There is a need for a device to improve the distribution of a liquid air-treating composition within a flexible enclosure of the type having a single dispensing chamber, in order that the full advantages of dispensing by permeation through polymeric materials can be realized.
There is a need for a simple, inexpensive device for supporting a flexible plastic pouch for dispensing air-treating vapors from a contained liquid. The device should serve to: isolate the pouch away from finished surfaces; eliminate the need for human contact with such pouch; allow good air circulation against the pouch; allow each visual inspection to determine when the pouch is empty; hold the contained liquid in good contact with a large portion of the inner surface of the permeable pouch to improve dispensing characteristics; and also protect the burstable impermeable inner container (such as a pouch within the permeable pouch) from premature, unintentional bursting. Given the number of functions such device would serve, low cost and simplicity are not easily achieved.
There is a need for such a device which may be readily adaptable for use as a so-called "small spaces" vapor dispenser, that is, a small, inexpensive vapor-dispensing device of a type suitable for placement in drawers, closets, small rooms, and the like. This invention provides all of the aforementioned advantages in a simple, inexpensive device useful as a "small spaces" vapor dispenser. This invention may also be used for larger vapor-dispensing devices, such as those which may be placed on a countertop or the like.